While this clusters RDF terms that are the same, it does not sort them.

Implementations are also free to provide extensions to "<" or ORDER BY to provide placing rows
with the same blank node together in the sort order.

The working group did not choose to make changes in this area of the specification during the "Features and Requirements" phase and the working group charter discourages any change that would alter the results of a query
that was valid according to SPARQL 1.0.

Therefore the working group has decided not to make a change in this area.

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